Cloning in cattle: from embryo splitting to somatic nuclear transfer

The ability to obtain genetically identical offspring in cattle (clones) is useful for research and for potential applications to breeding schemes. Experimental possibilities for generat- ing such animals have evolved considerably in the last two decades. Embryo splitting has become a relatively simple technique but is limited to twinning. Embryonic nuclear transfer has improved and is associated with sexing to generate sets of clones despite a great variability of results between par- ent embryos. The factors of progress are reviewed here. Recently, somatic cells used as a source of nuclei in bovine nuclear transfer has been demonstrated. Here we present the results of the devel- opmental potential of nuclei from skin and muscle cells. © Inra/Elsevier, Paris. bovine / embryo cloning / somatic cloning / nuclear transfer Rsum ― Clonage chez les bovins : de la bissection d'embryons jusqu'au transfert de noyaux somatiques. L'obtention de bovins gntiquement identiques (clones) est utile pour la recherche et les applications potentielles en slection. Les possibilits exprimentales de produire de tels ani- maux ont considrablement volu depuis 10 ans. La bissection d'embryons est devenue une tech- nique relativement simple mais elle est limite l'obtention de jumeaux. Le clonage embryonnaire a progress et peut tre associ au sexage pour faire natre des clones de veaux, malgr une grande varia- bilit selon les embryons donneurs. Les facteurs de progrs sont analyss dans cette revue. Rcem- ment l'aptitude de noyaux somatiques tre reprogramms aprs transfert nuclaire a t dmontre et nous prsentons les premiers rsultats obtenus partir de cellules de peau ou de muscle.